201027953 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種通訊晶片之應用，尤指一種通訊晶片 内同相與正交不平衡（IQ imbalance )之校正方法。 【先前技術】 一般通訊晶片内之類比元件，例如混波器（mixer )、本 地震盪器（local oscillator)或低通濾波器（1〇w_passfiher) 等，皆有可能在訊號通過時使該訊號之同相和正交成分產 • 生振幅及相位之不匹配，此即該等類比元件之同相與正交 響應之不平衡。 傳統校正該等類比元件之同相與正交響應不平衡之方法 係先產生一數位基頻測試訊號，並將該數位基頻測試訊號 、’二由數位至類比轉換後通過該等類比元件以產生具有振幅 及相位不匹配之類比高頻訊號。接著，將該類比高頻訊號 通過一混波器以產生其降頻訊號，並經由類比至數位轉換 後分析其頻譜，以決定相應於該等類比元件之同相與正交 ® 響應不平衡之校正值。 然而，該混波器係位於該數位基頻測試訊號之回饋路 徑，故其僅於校正該等類比元件之同相與正交響應不平衡 時作用，而在正常訊號發送模式時並不作用，故降低通訊 晶片内整體元件之使用率。 因此，若能設計一種同相與正交不平衡之校正方法，使 其可省略通過該混波器之步驟，則不僅可節省設計通訊晶 片時之成本及該通訊晶片之面積，亦能提高該通訊晶片各 135528.doc 201027953 元件之使用效率。 【發明内容】 本發明之一實施例揭示一種校正類比元件之方法，其係 利用功率放大器之非線性放大之特性以取代習知之據波 器，故相較於習知技術具有節省電路面積之優點。201027953 IX. Description of the Invention: [Technical Field] The present invention relates to a communication chip application, and more particularly to a method for correcting in-phase and quadrature imbalance in a communication chip. [Prior Art] Analog components in a general communication chip, such as a mixer, a local oscillator, or a low-pass filter (1〇w_passfiher), are all possible to make the signal when the signal passes. The in-phase and quadrature components produce a mismatch in amplitude and phase, which is the imbalance between the in-phase and quadrature response of the analog components. The conventional method for correcting the in-phase and quadrature response imbalance of the analog components first generates a digital fundamental frequency test signal, and converts the digital fundamental frequency test signal, 'two from digital to analog, and then passes through the analog components to generate An analog high frequency signal with amplitude and phase mismatch. Then, the analog high frequency signal is passed through a mixer to generate its down-converted signal, and the spectrum is analyzed by analog-to-digital conversion to determine the correction of the in-phase and quadrature® response imbalance corresponding to the analog components. value. However, the mixer is located in the feedback path of the digital baseband test signal, so it only acts to correct the in-phase and quadrature response imbalance of the analog components, but does not function in the normal signal transmission mode. Reduce the use of the overall components in the communication chip. Therefore, if a correction method of in-phase and quadrature imbalance can be designed so that the steps of passing the mixer can be omitted, the cost of designing the communication chip and the area of the communication chip can be saved, and the communication can be improved. The efficiency of the components of the 135528.doc 201027953 components. SUMMARY OF THE INVENTION One embodiment of the present invention discloses a method for correcting analog components, which utilizes the characteristics of nonlinear amplification of a power amplifier to replace a conventional data filter, thereby having the advantage of saving circuit area compared with the prior art. .
❹ 本發明t-實施例之校正類t匕元件之方法包含下列步 驟：產生-基頻之第-訊號；將該第—訊號通過欲校正^ 類比元件以產生一第二訊號；將該第二訊號經由—功率放 大ι§以產生一第二訊號’其中該功率放大器係操作於非線 f生區域，過遽該弟二訊號之尚頻成分以.產生一基頻之第四 訊號；以及若該第四訊號有同相與正交不平衡現象，則調 整相應於該同相與正交不平衡之校正值，並根據該校正值 再執行產生該第一訊號之步驟。 本發明之另一實施例之校正類比元件之電路包含—功率 放大器、一低通濾波器、一類比至數位轉換器和一頻譜分 析單元。該功率放大器用以放大該等類比元件之輪出訊 號，並操作於非線性區域。該低通濾波器用以過濾該功率 放大器之輪出訊號。該類比至數位轉換器用以轉換該低通 遽波器之輸出訊號。該頻譜分析單元用以分析該類比至數 位轉換器之輸出訊號。 本發明之另一實施例之無線收發器之校正方法包含下列 步驟：產生一基頻之第一訊號；將該第一訊號通過欲校正 之類比元件以產生一之第二訊號；將該第二訊號經由一功 率放大器以產生一第三訊號’其中該功率放大器係操作於 135528.doc -6- 201027953 非線性區域；過渡該第三訊號之高頻成分以產生-基頻之 第四訊號；以及將該第四訊號以一載頻發射，並判斷若該 第四訊號有同相與正交不平衡現象，則調整相應於該同相 與正交不平衡之校正值，並根據該校正值再執行產生該第 一訊.號之步驟。 本發明之另一實施例之無線發射裝置包含一功率放大 器、-低通濾波器、—類比至數位轉換器、―頻譜分析單 元以及-天線。該功率放大器用以放大該等類比元件之輸 O A訊號’並操作於非線性區域。該低通濾波器用以過渡該 功率放大器之輸出訊號。該類比至數位轉換器用以轉換該 低通濾波器之輸出訊號。該頻譜分析單元用以分析該類比 至數位轉換器之輸出訊號。該天線以一載頻傳送該輸出訊 號。 【實施方式】 圖1顯示本發明之一實施例之校正同相與正交不平衡之 籲 方法之流程圖。在步驟101，產生一基頻之第一訊號，並進 入步驟102。在步驟1〇2，將該第一訊號通過欲校正同相與 正交不平衡之類比元件，用以產生一第二訊號，並進入步 驟103在步驟103，將該第二訊號通過一功率放大器以產 生一第三訊號，其中該功率放大器係操作於非線性區域， 並進入步驟104。在步驟104，將該第三訊號通過一低通濾 波益以產.生基頻之第四訊號’並進入步驟。在步驟 105 ’分析该第四訊號之頻率響應，並進入步驟1〇6。在步 驟1〇6,若該第四訊號之頻率響應顯示其有同相與正交不平 135528.doc 201027953 衡現象’則進入步驟107，否則結束該校正流程。在步驟 107,根據該第四訊號之頻率響應所顯示之同相與正交不平 衡調整該等類比元件之增益及振幅校正值，並重新執行步 驟 101。 本發明之一實施例之無線收發器之校正方法相似於圖1 所示之流程圖’其係於步驟107將該第四訊號以一載頻發 射，以達到發射無線訊號之目的。 圖2顯示本發明之一實施例之同相與正交不平衡之校正 電路。該校正電路200包含數位至類比轉換器21〇和22〇、低 通渡波器230和240、可變增益放大器250和260、本地放大 斋270和280、混波器290和300、一加法器31〇、一功率放大 器320、一低通渡波器330、一類比至數位轉換器34〇、一頻 譜分析單元350和一振幅相位調整單元36〇。該數位至類比 轉換器21 0、低通濾'波器230、該可變增益放大器250、本地 放大器270和該混波器290係該校正電路200之同相訊號路 徑1該數位至類比轉換器220、低通濾波器240、該可變增 盈放大态260、本地放大器280和該混波器3〇〇係該校正電路 2 0 0之正父訊號路控。該低通濾波器〇、該類比至數位轉 換器340和該頻譜分析單元35〇係該校正電路2〇〇之回儀路 徑。 將圖1之校正方法應用於圖2之校正電路2〇〇，產生一基頻 之第一訊號並使其通過該校正電路2〇〇之同相訊號路徑及 正父訊號路徑，並經由該加法器3丨〇相加該兩路徑輸出之訊 號以產生一第二訊號。在本實施例中，若該基頻之第一訊 135528.doc 201027953 號為一弦波訊號，st 够 ^现，則該第二訊號可表示為： £’}，其中Re表示取括弧内之實部訊號， g和θ㈣表示㈣該兩路徑之類比元件後所產生之增益 及相位之不匹配，而主_ 而〇。表不該第二訊號之中心頻率。若該 第一訊號無振幅及相位.之.尤沉献 Θ 等 於0 。該 第 (l + geje^ eJal + Ll 2 J l 2 J e ja3t ’位之不匹配’亦即該同相訊號路徑及 W | = Refce7ev + A：2e* ]e~ 卜其頻率響 應係如圖3所不’纟中頻率為心+ω之訊號為原本之訊號， 而頻率為ω e · ω之訊號則為因增益及相位不匹配而產生之 訊號。 復參圖2，本實施例係利用該功率放大器320之非線性放 大之特！·生以使該第二訊號通過而產生一第三訊號。圖4 顯不該功率放大器32〇之增益響應圖。如圖4所示，該功率 放大器320之增益響應分為線性放大區及非線性放大區。在 ❹ 正常訊號發送時，該功率放大器320係操作於線性放大區； 而在校正同相與正交不平衡時，該功率放大器32〇係操作於 非線ϋ放大區。該非線性放大之特性可由下列多項式表 不：y = Wfoc + Cx2+办3+…，其中χ為輸入，而y為輸出。該一次 項之響應係使該第三訊號保留原本該第二訊號之成分，而 該向次項部分則使該功率放大器320之作用類似於一混波 器而使該第三訊號具有該第二訊號之降頻成分。 該第三訊號接著通過該低通濾波器330,其可由一封包檢 135528.doc 201027953 測器（envelope detector)實現，以保留該第三訊號之低頻 毅’亦即第四訊號。該第四訊號經過該類比至數位轉換 器340之轉換後，經由該頻譜分析單元别分析其增益及相 位之不匹配，亦即該之值。若g不為㈣不為〇,則 於該振幅相位調整單元360儲存其校正值以調整該正交訊 號路控之輸入訊號之振幅及相位。 ❷ ❹ 圖5顯示該校正電路200各點訊號校正前後之頻率響應 圖。圖5A顯示該第二訊號之頻率響應。如圖5a所示，該第 二訊號於校正前具有一因同相與正交不平衡而產生之訊 號。圖5B顯示該第三訊號之頻率響應。如圖5b所示，該第 三訊號具有該第二訊號於各個頻率之複製訊號。B5c顯示 該第四訊號之頻率響應。 本發明之一實施例之無線發射裝置相似於圖2所示之電 路’其另包含—天線’以利用一載頻傳送該功率放大器320 之輸出訊號。 較佳的，亦可於該同相與正交不平衡校正後進行該功率 放大器320之非線性放大之校正。圖6顯示本發明之一實施 例之功率放大器之非線性放大之校正電路。該校正電路_ 包含一預失真電路610、一校正演算電路62〇、一數位至類 比轉換II63G、-類比至數位轉換器64()、—調變及升頻電 路650、一調變及降頻電路66〇和該功率放大器32〇。該數位 至類比轉換器630及該調變及升頻電路65〇可由該校正電路 2〇〇之同相訊號路徑及正交訊號路徑實現。該類比至數位轉 換器640可由該類比至數位轉換器34〇實現，而該調變及降 135528.doc -10- 201027953 頻電路660可包含該低通濾波器330。 在該同相與正交不平衡校正後，即利用比較該數位至類 比轉換器630之輪入訊號及該類比至數位轉換器64〇之輸出 5號亦即該第一及第四訊號.，於該校正演算電路.620進行 運算以更新該預失真電路610，並藉此補償該功率放大器 =〇~之非線性放大之特性。較佳的，該校正演算電路62〇之 演算法可為最小均方演算（least mean square , lms )法， 而該失真電路6i〇可由一查找表實現。 綜上所述，本實施例之同相與正交不平衡之校正方法係 利用既有之功率放大器其非線性放大特性而不需額外增加 一混波器，故可節省電路面積及成本。另一方面，本實施 例可利用校正後之電路進行該功率放大器之非線性放大特 性之校正以提高其校正之準確度。 本發明之技術内容及技術特點已揭示如上，然而熟悉本 項技術之人士仍可能基於本發明之教示及揭示而作種種不 背離本發明精神之替換及修倚。因此，本發明之保護範圍 應不㈣實施例所揭示者，而應包括各種不f離本發明之 替換及修飾，並為以下之申請專利範圍所涵蓋。 【圖式簡單說明】 圖1顯示本發明之一實施例之校正同相與正交不平衡之 流程圖； 圖2顯示本發明之—實施例之同相與正交不平衡之校正 電路； 圖3顯示本發明之一實施例之頻率響應圖； 135528.doc -11- 201027953 圖4顯示本發明之一實施例之增益響應圖 圖5顯示本發明之一實施例之另—頻率響應圖 之非線性放大 圖6顯示本發明之一實施例之功率放大哭 之校正電路。 ❿The method of the t-component of the t-embodiment of the present invention comprises the steps of: generating a first-signal of the fundamental frequency; passing the first signal through the analog component to generate a second signal; The signal is amplified by a power amplifier to generate a second signal, wherein the power amplifier operates in a non-lined region, and the frequency component of the second signal is generated to generate a fourth signal of the fundamental frequency; The fourth signal has an in-phase and quadrature imbalance phenomenon, and the correction value corresponding to the in-phase and quadrature imbalance is adjusted, and the step of generating the first signal is performed according to the correction value. A circuit for correcting analog components of another embodiment of the present invention includes a power amplifier, a low pass filter, an analog to digital converter, and a spectral analysis unit. The power amplifier is used to amplify the round-trip signals of the analog components and operate in a non-linear region. The low pass filter is used to filter the turn-off signal of the power amplifier. The analog to digital converter is used to convert the output signal of the low pass chopper. The spectrum analysis unit is configured to analyze the output signal of the analog to digital converter. A method for correcting a wireless transceiver according to another embodiment of the present invention includes the steps of: generating a first signal of a fundamental frequency; passing the first signal through an analog component to be corrected to generate a second signal; The signal is generated by a power amplifier to generate a third signal, wherein the power amplifier operates in a nonlinear region of 135528.doc -6-201027953; and the high frequency component of the third signal is transitioned to generate a fourth signal of the fundamental frequency; Transmitting the fourth signal by a carrier frequency, and determining that if the fourth signal has an in-phase and quadrature imbalance phenomenon, adjusting a correction value corresponding to the in-phase and quadrature imbalance, and performing the generation according to the correction value The first step of the number. A wireless transmitting apparatus according to another embodiment of the present invention includes a power amplifier, a low pass filter, an analog to digital converter, a spectrum analyzing unit, and an antenna. The power amplifier is used to amplify the input O' signal of the analog components and operate in a non-linear region. The low pass filter is used to transition the output signal of the power amplifier. The analog to digital converter is used to convert the output signal of the low pass filter. The spectrum analysis unit is configured to analyze the output signal of the analog to digital converter. The antenna transmits the output signal at a carrier frequency. [Embodiment] Fig. 1 is a flow chart showing a method of correcting in-phase and quadrature imbalances according to an embodiment of the present invention. In step 101, a first signal of a fundamental frequency is generated and the process proceeds to step 102. In step 1〇2, the first signal is passed through an analog component for correcting the in-phase and quadrature imbalance to generate a second signal, and proceeds to step 103. In step 103, the second signal is passed through a power amplifier. A third signal is generated, wherein the power amplifier operates in a non-linear region and proceeds to step 104. In step 104, the third signal is passed through a low pass filter to generate a fourth signal of the fundamental frequency and proceeds to the step. The frequency response of the fourth signal is analyzed at step 105' and proceeds to step 1〇6. In step 1〇6, if the frequency response of the fourth signal shows that there is an in-phase and quadrature unevenness, the process proceeds to step 107, otherwise the calibration process ends. In step 107, the gain and amplitude correction values of the analog components are adjusted according to the in-phase and quadrature imbalances displayed by the frequency response of the fourth signal, and step 101 is re-executed. The method for correcting the wireless transceiver of one embodiment of the present invention is similar to the flowchart shown in FIG. 1 which is used in step 107 to transmit the fourth signal at a carrier frequency for the purpose of transmitting a wireless signal. Fig. 2 shows a correction circuit for in-phase and quadrature imbalance of an embodiment of the present invention. The correction circuit 200 includes digital to analog converters 21A and 22A, low pass ferrites 230 and 240, variable gain amplifiers 250 and 260, local amplifiers 270 and 280, mixers 290 and 300, and an adder 31. A power amplifier 320, a low pass waver 330, an analog to digital converter 34A, a spectrum analyzing unit 350, and an amplitude phase adjusting unit 36A. The digital to analog converter 210, the low pass filter 230, the variable gain amplifier 250, the local amplifier 270, and the mixer 290 are the in-phase signal path 1 of the correction circuit 200. The digital to analog converter 220 The low pass filter 240, the variable gain amplification state 260, the local amplifier 280, and the mixer 3 are the positive signal path of the correction circuit 200. The low pass filter 〇, the analog to digital converter 340 and the spectral analysis unit 35 are the return path of the correction circuit 2〇〇. Applying the calibration method of FIG. 1 to the correction circuit 2〇〇 of FIG. 2, generating a first signal of a fundamental frequency and passing it through the in-phase signal path and the positive-parent signal path of the correction circuit 2, and passing the adder 3丨〇 Add the signals output by the two paths to generate a second signal. In this embodiment, if the first signal of the fundamental frequency is 135528.doc 201027953, which is a string signal, and st is sufficient, the second signal can be expressed as: £'}, where Re indicates that the arc is enclosed in the arc. The real signal, g and θ(4), represent (4) the mismatch between the gain and phase produced by the analog components of the two paths, and the main _ and 〇. The center frequency of the second signal is not shown. If the first signal has no amplitude and phase, it is equal to 0. The first (l + geje^ eJal + Ll 2 J l 2 J e ja3t 'bit mismatch' is the same phase signal path and W | = Refce7ev + A: 2e* ] e~ The signal whose frequency is heart +ω is the original signal, and the signal whose frequency is ω e · ω is the signal generated by the gain and phase mismatch. Referring to Figure 2, this embodiment uses the signal. The non-linear amplification of the power amplifier 320 is generated by the second signal to generate a third signal. Figure 4 shows the gain response of the power amplifier 32. As shown in Figure 4, the power amplifier 320 The gain response is divided into a linear amplification region and a nonlinear amplification region. The power amplifier 320 operates in a linear amplification region when the normal signal is transmitted, and the power amplifier 32 operates in the correction of the in-phase and quadrature imbalance. In the non-linear ϋ amplification region, the nonlinear amplification characteristic can be represented by the following polynomial: y = Wfoc + Cx2+ do 3+..., where χ is the input and y is the output. The response of the primary term keeps the third signal Originally the component of the second signal, and the direction The portion of the power amplifier 320 is similar to a mixer such that the third signal has a frequency down component of the second signal. The third signal is then passed through the low pass filter 330, which can be checked by a packet. 135528.doc 201027953 The envelope detector is implemented to retain the low frequency of the third signal, that is, the fourth signal. After the fourth signal is converted by the analog to digital converter 340, the spectrum analysis unit is The gain and phase mismatch, that is, the value, is analyzed. If g is not (4) is not 则, the amplitude phase adjustment unit 360 stores the correction value to adjust the amplitude of the input signal of the orthogonal signal path and Figure 显示 shows the frequency response of the correction signal 200 before and after the signal correction. Figure 5A shows the frequency response of the second signal. As shown in Figure 5a, the second signal has a phase inconsistency before correction. The signal generated by the quadrature imbalance. The frequency response of the third signal is shown in Figure 5B. As shown in Figure 5b, the third signal has a copy signal of the second signal at each frequency. B5c displays the fourth signal. The frequency response of the embodiment of the present invention is similar to the circuit shown in FIG. 2, which additionally includes an antenna for transmitting the output signal of the power amplifier 320 using a carrier frequency. The nonlinear amplification correction of the power amplifier 320 is performed after the in-phase and quadrature imbalance correction. Figure 6 shows a non-linear amplification correction circuit of the power amplifier according to an embodiment of the present invention. The correction circuit _ includes a pre-distortion Circuit 610, a correction calculation circuit 62A, a digital to analog conversion II63G, an analog to digital converter 64(), a modulation and upconversion circuit 650, a modulation and frequency reduction circuit 66, and the power amplifier 32. Hey. The digital-to-analog converter 630 and the modulation and up-conversion circuit 65 can be implemented by the in-phase signal path and the orthogonal signal path of the correction circuit 2〇〇. The analog to digital converter 640 can be implemented by the analog to digital converter 34, and the modulation and subtraction 135528.doc -10- 201027953 frequency circuit 660 can include the low pass filter 330. After the in-phase and quadrature imbalance correction, that is, using the round-in signal of the digital-to-analog converter 630 and the output 5 of the analog-to-digital converter 64, that is, the first and fourth signals, The correction calculation circuit .620 performs an operation to update the predistortion circuit 610 and thereby compensates for the nonlinear amplification characteristics of the power amplifier. Preferably, the algorithm of the correction calculation circuit 62 can be a least mean square (lms) method, and the distortion circuit 6i can be implemented by a lookup table. In summary, the in-phase and quadrature imbalance correction method of the present embodiment utilizes the nonlinear amplification characteristics of the existing power amplifier without adding an additional mixer, thereby saving circuit area and cost. On the other hand, in this embodiment, the corrected circuit can be used to correct the nonlinear amplification characteristics of the power amplifier to improve the accuracy of the correction. The technical contents and technical features of the present invention have been disclosed above, but those skilled in the art can still make various alternatives and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be construed as being limited by the scope of the invention, and should be construed as being limited by the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing correction of in-phase and quadrature imbalance according to an embodiment of the present invention; FIG. 2 is a diagram showing an in-phase and quadrature imbalance correction circuit according to an embodiment of the present invention; Frequency response diagram of an embodiment of the present invention; 135528.doc -11- 201027953 FIG. 4 shows a gain response diagram of an embodiment of the present invention. FIG. 5 shows a nonlinear amplification of another frequency response diagram according to an embodiment of the present invention. Figure 6 shows a power amplification crying correction circuit in accordance with one embodiment of the present invention. ❿
【主要元件符號說明】 101-107 步驟 200 校正電路 210 數位至類比轉換器 220 數位至類比轉換器 230 低通濾波器 240 低通濾波器 250 可變增益放大器 260 可變增益放大器 270 本地震盪器 280 本地震盪器 290 混波器 300 混波器 310 加法器 320 功率放大器 330 低通濾波器 340 類比至數位轉換器 350 頻譜分析單元 360 振幅相位調整單元 600 校正電路 610 預失真電路 620 校正演算電路 630 數位至類比轉換器 640 類比至數位轉換器 650 調變及升頻電路 660 調變及降頻電路 135528.doc •12-[Major component symbol description] 101-107 Step 200 Correction circuit 210 Digital to analog converter 220 Digital to analog converter 230 Low pass filter 240 Low pass filter 250 Variable gain amplifier 260 Variable gain amplifier 270 This oscillator 280 The present oscillator 290 mixer 300 mixer 310 adder 320 power amplifier 330 low pass filter 340 analog to digital converter 350 spectrum analysis unit 360 amplitude phase adjustment unit 600 correction circuit 610 predistortion circuit 620 correction calculation circuit 630 digital To analog converter 640 analog to digital converter 650 modulation and upconversion circuit 660 modulation and frequency reduction circuit 135528.doc •12-